Roller shutter for shop fronts, doors, windows, and the like



y 6, 2 B. NEGRINI 1.720.850

RQLIJER SHUTTER FOR SHOP FRONTS, DOORS, WINDOWS, AND THE LIKE Filed March 25, 1927 jyfwwygf Patented July 16, 1929.

UNITED STA TES PATENT OFFICE.

BRUNO NEGRINI, 0F BOLOGNA, ITALY.

ROLLER SHUTTER FOR SHOP FRONTS, DOORS, WINDOWS, AND THE LIKE.

Application filed March 25, 1927, Serial No.

This invention relates to an improved roller-shutter for shop fronts, doors and windows and the like, constructed from rectangular metal sheets or slats connected to each other by interengaging spirally formed beadings constructed along their longitudinal edges so as to allow the coupling of the slats and the shutter being wound up on a roller.

The object of the present invention is to provide a form of metal sheet or metal slat which presents essential advantages in comparison to the metal slats hitherto employed for the manufacture of roller-shutters. The form of the slats employed makes it possible to manufacture the spirally formed beading of the sheet with a cold bending operation and in one passage of the blank across the bending machine and without requiring any heating of the sheet. Also, owing to variation of the heights of the sheets in blind manufacture with the improved roller-shutter according to the invention the rolling or winding-up of the blind can be effected in a smaller space than the roller-shutters hitherto known.

Another advantage of this shutter according to the present invention consists in this that it presents when in use a substantial plane surface without any sharp edges and is of superior strength, as besides the ribs formed by the spirally bent beading, additional bends are formed which run parallel and in the proximity to these bent edges and which efiiciently contribute to the resistance of the shutter.

The invention consists in an improved roller shutter for shop fronts, doors, windows and the like constructed from rectangular metal sheets connected to each other by spirally formed beadings constructed along their longitudinal edges, the said beads being situated at the same side of the plane of the slat,-characterized in that one edge has a bead having a curvature which begins on the slat itself adapted to form a tubular sleeve to fit snugly within a tubular sleeve of a corresponding bead along the edge of the slat to be coupled and which latter bead is such that the curvature does not begin upon the slat itself but upon a line situated in a plane which passes through the centre of the first mentioned bead and parallel with the plane of the slat, a straight wall portion inclined at an angle of degrees to 178,447, and in Great Britain April 9, me.

the plane of the slat connecting the slat with the bead.

In the accompanying drawings which illustrate one way of carrying the invention into effect,

Figure 1 shows a vertical section of a shutter rolled up on its roller, a part of the shutter being shown in the lowered position.

Figure 2 shows a detail of the interengaging edges of the slats.

In these figures the metallic slats present along their longitudinal edges spirally formed headings which are all situated at the same side of the plane of the slats and adapted to allow the edges of the slats to interongage as well as to be wound up on a reel. As seen in the drawing each slat has along one of its longitudinal edges a bead 1, the curvature of which beginning upon the slat itself is adapted to form a tubular sleeve to fit snugly within a tubular sleeve of a corresponding bead 2 along the edge of the next slat to be coupled. The bead 2 does not begin upon the slat itself but upon a line a-m situated in a plane which passes through the centre of the bead 1 and parallel with the plane of the slat, the head 2 being connected with the slat by a straight side portion 3 which is inclined at an angle of 45 degrees relatively 'to the plane of the slat. This particular form of the slats, as clearly shown in Figure 1, permits the shutter being rolled within the very smallest space, as the single ribs formed by the interengaging edges become partially seated within the grooves or seats formed by the said edges and the bend 4 of the next inner winding of the shutter. The bend 4 besides presents a useful means of reinforcing the slat. The shutter made up of slats of the type specified presents in an extended condition substantially a plane surface without any sharp edges on the single slats. The slats are divided in groups each group containing the same number of slats as the polygonal reel has sides. The height of the slats in each group is the same but the height of the slats in the different groups increase from the top to the bottom of the blind so that the groups of slats when wound up may lie as near to one another as possible so as to occupy the smallestpossible space as clearly shown in Fig. 1 of the drawi gs.

Having now particularly described and ascertained the nature of my said invention first mentioned beading of two adjacent sheets and permitting relative movement of the latter, the offset portions of the sheets presentin well defined seat portions and the indivldual sheets being so proportioned as to width that when the shutter is rolled up the headings of one convolution of the shutter occupy the seat portions of the underlying sheets.

In testimony whereof I have signed my name to this specification.

BRUNO NEGRINI. 

